Remote control system



y 1942- G. GILLIVER ETAL v 2,290,233

REMOTE CONTROL SYSTEM Filed June 5, 1940 3 Sheets-Sheet 2 1 1 5 -VW A 2'a J Yaw? Gilbert 66116061, George Fran/e Tag BY Geoggefiedermk 5/20 an y1942- a. GILLIVER EI'AL 2,290,233

REMOTE CONTROL SYSTEM Filed June 5, 1940 3 Sheets-Sheet 3 L i *1 LiGemye frgrz/o 7225;; BY Gewggefiederw/afiko 1;

Patented July 21, 1942 UNITED STATES? PATENTOFFECE REMOTE CONTROI LSYSTEM Application June 5, 1940, Serial No. 338,940 In Great BritainJune 15, 1939 7 Claims.

This invention concerns improvements relat street lighting, but isapplicable also to other. purposes, such as the control oftariff-changing operations.

It has already been proposed that remote control should be exercisedover a three-phase system by producing a variation of phase angle of oneof the three line voltages in relation to the other two by theapplication of an auxiliary transformer with the eflect of generating onone of the three phases an auxiliary voltage at 90 to the voltage of.-at phase.

According to the present invention, in a remote-control or signallingsystem of the kind set forth, variations of phase angle and magnitude oftwo of the line voltages of the system in relation to the third areproduced for remote control or signalling purposes by an auxiliarytransformer which generates an auxiliary voltage at an appropriate angleto one of the two line voltages and at another appropriate angle to theother of the said voltages.

These variations may be produced ata point on the high-tension side ofthe system and, when so produced, can be received at another point onthe same side or at a point on the low-tension side.

When the signals are transmitted at a point on a four-wire system theresulting variation in magnitude of the line voltages will give rise toa currentin the fourth or neutral wire and a receiving arrangement orrelay adapted for operation by said current may be provided.

when, however, the variations are produced'at a point on a three wiresystem there is no such current for operating a relay and a receivingarrangement adapted for operation solely byv the variation of phaseangle of the line voltage is employed.

It is usual to employ four-wire low tension systems fed from three-wirehigh tension systems through delta-star transformers.

If the variations are produced at a point at a pointon the four-wire lowtension system a receiving arrangement or relay adapted for operation byvariations in phase angle must be employed. v x One-method of utilisingthis phase disturbance to operate a relay is, according to theseimprovements, to. connect the voltage coil of a relay .across theaflected lines and the series coil of said relay between the remainingline and neutral, so that the flux due to the pressure coil alters inphase relatively to the flux due to the series coil upon receipt of asignal.

Another method of utilising the phase disturbance for operating a relayis to connect the coil of therelay in a balanced circuit associated withthe affected lines, said'circuit including resistance, capactance andinductance. so chosen that under normal conditions no current flows inthe coil whereas when a phase disturbance'is produced by signalling, thebalance of the circuit is upset and a current flows in the coilproducing a flux adapted for closing contacts.

In order that the invention may be readily understood reference isdirected to the accompanying drawings wherein- Figure 1 is a diagram ofa transmitting arrangement in accordance with one embodiment of theinvention.

Figures 2 and 3 are vector diagrams of line voltages showing variationsproduced by transmitting arrangements according to this invention.

Figure 4 is a diagram of a receiving arrangement in. accordance with theinvention.

Figures 5 and- 6 are circuit diagrams of modified receivingarrangements.

Figure 7 is a circuit diagram of transmitting and receiving arrangementsin accordance with the invention, the transmitting arrangement being ata point on a three-wire system and the receiving arrangement at a pointon a 4-wire system fed from the 3-wire system.

- Figure 8 is a vector diagram of the line voltages in Figure '1. 1

Figures 9-12 are'circuit diagramsof modifications of the receivingarrangement shown in Figure 7.

Referring to Figure l the secondary winding 4 of a transformer isincluded in the line 3 of a three-phase distribution system comprisingwires I, 2 and 3. The primary winding 5 of the transformer can beconnected, by means of a reversing switch 6, in either direction acrossthe lines I and 2. A third winding 1 of the transthe three wire hightension system and received former is normally short circuited by aswitch 8.

/ duced-voltage nitude are nearly equal.

2 Consequently, under normal circumstances, the transformer acts as a.short-circuitedcurrent transformer and merely introduces a negligibleimpedance into the line 3.

To transmit a' signal, the short-circuiting switch 8 is opened and thereversing switch 6 is closed on one side or the other. If desired, theswitches 6 and 8 maybe mechanically or electromagnetically coupledtogether for this operation, as shown. By this means, a voltage isintroduced Thus the voltage Vzsls retarded in phase through an angle a.and increased in magnitude while the voltage Varis also retarded inphase -(through angle 3) but reduced in magnitude.

For the other direction of closure of the switch 6, the opposite efl'ectis produced as shown in Figure 3. The voltage 12 introduced -into line 3is in phase with voltage V1: resulting in a readvanced through an anglep and an increased voltage 1 Vii advanced through an angle a.

With the introduced voltage 12 or v at 60 or 120 to the affectedline-voltages, the angles a and p and the increases and decreases in maWith other feasible angles, one line voltage is affected more seriouslythan the other and greater disturbance ,of the system results.

A receiving arrangement more particularly for use on a high tensionsystem is shown in Figure 4 and comprises two transformers having theirsecondaries-9 and Ill connected in opposition as indicated by the arrows60 and 6|. The primary ll of one transformer is connected, in serieswith a condenser l2 and resistance It, across the lines I and 2 betweenwhich the voltage V1: is not affected. The primary ll of the othertransformer is connected, in series with a resistance l5, across one ofthe pairs of' lines whose voltage is affected as described above, sayacross lines 2 and 3 as shown.

Without the condenser l2, the current in the transformer 9, ll wouldnormally lead that in transformer IO, M by 120. By making the condenserl2 of appropriate capacity this lead may be increased to 180. ;Thevoltages across the secondaries 9 and lflare then normally in phaseopposition, as indicated, and no voltage appears across theextremeterminals of the secondaries Band ll.

As soon as a signal is transmitted. the angle between the line voltagesV1: and V1: become changed from l20 to 1209+: or 120-p according to thedirection of closure of the switch 6 of the transmitting arrangement.The voltages across the secondaries 9 and ID no longer balance and avoltage appears across the extreme aaeaaas terminals thereof which canbe utilised for actuating a relay or other receiving means. This voltageis of opposite phase according to the diphase.

The voltage 0 aifects the voltages V31;

The relay 62 may be of the wattmeter type and include a disc 63 normallylocated in the position shown. that is arranged to cooperate with setsof contacts 65 and 66 for closing one set or the other depending uponthe direction of rotation of the disc 63. A coil 61 connected forenergization between lines I and 2 cooperates with coil 68 energizedfrom secondaries 9 and ill in a well known manner to rotate the disc 63in one direction or the other in accordance with the phase of theapplied control voltage.

Receiving arrangements for use, more particularly on the low-tensionside of a three phase supply system will now be described.

Figure 5 shows such an arrangement which depends for its operation on avariation in the sum of the line voltages and is therefore suitable onlywhen the signals are transmitted entirely over a 4-wire three phasesystem. The arrangement comprises a transformer with a single secondaryl6 and three primaries I'i', l8 and I9 connected in series withrespective resistances 20, 2| and 22, in star between the lines I, '2and 3 and the neutral N. Normally there is no flux in the core of thistransformer and no voltage is induced in the secondary l6. However, whena signal is transmitted, the line voltages V12, V31 and V23 becomeunbalanced and a voltage is induced in the secondary l6 whose phasedepends on the direction of closure of the switch 6 of the transmittingarrangement. This voltage can be utilised to operate an A. C. relay,such as the relay 62, as set forth above.

The transformer comprising the windings l6, l1, l8 and I! may bedispensed with if'use is made of a three phase relay which consists of awatt-hour meter provided with contacts clos-.

able by rotation of its disc. There may be separate contacts closable byrotation in each of the two directions. As shown in Figure 6, thevoltage. coil of a watt-hour meter 23, similar to the relay '62previously described, is wound in signal is received, the out of balancecurrent in the said coils 2|, 25 and 26 produces a flux in the magnetand a torque on the disc. The I direction of rotation of the disc willdependupon the phase of the voltage introduced.

It is usual to employ distribution systems comprising 4-wlr three phaselow tension systems fed from 3-wire three phase high tension systems. 1

As hereinbefore stated if an auxiliary voltage is introduced into one ofthe lines of a 3-wire high tension systemin accordance with theseimprovements no variation can be produced in the sum of the linevoltages and therefore no The disc 63 carries a pin 64 I on and off astreet light 15.

scribed are particularly adapted for receiving,

at a point on a 'i-wire low tensionsystem, sigvoltage coil flux can bemade 90 out of phase torque on the meter disc. When a signal istransmitted by introducing the auxiliary voltage in high tension line 3the phase of voltnals transmitted in accordance with the invention at apoint on a 3-wire high tension system from which the low tension systemis fed by way of delta-star transformers.

in Figure 7 a transmitting arrangement as described with reference toFigure l is shown connected to a point on the lines I, 2 and 3 of a3-wire high tension system feeding the lines I, 2 and 3 of a 4-wlre lowtension system through a delta-star transformer 3|. Referring to thevector diagram (Figure 8) the normal high ten-.

sion line voltages are represented by the vectors in full lines V12, V31and V23. The efiect of opening the switch 3 and closing the switch 8(Figure '7) in one direction is to introduce an auxiliary voltage 0 andto advance the vectors V31 and V2: through angles a and 5 respectivelyas described with reference to Figure 3. The normal low tension linevoltages are represented by the full line vectors VH2, V3 1 and V2 3 Thephase displacement through angles a and p of the vectors V31 and V2:disturbs the phase relationship of all the low tension lines voltages,resulting in voltages 3: 3'1: 1 The two former are only slightlydisturbed but,

as can be seen from the diagram, the voltage 3 is the result of aserious disturbance in phase, infact a quadrature component 0' equal to.twice the injected voltage v (referredto the low tension system) isintroduced into the voltage V2 3 The effect of closing the switch 8 inthe other direction is to retard the phase of vectors Va: and V2:through angles 5 and a respectively as described with reference toFigure 2 and although not illustrated it will be understood that theeffect on the low tension system is to introduce a quadrature componentinto the voltage V2 3 of equal magnitude to the voltage 11 but ofopposite phase.

This considerable disturbance of the phase of voltage V2 2 may beutilised to operate a receiving arrangement such as is shown on theright hand or low tension side of Figure 7, in

which the voltage coil 32 of a relay 62, described hereinbefore, isconnected across the affected lines (lines 2 and 3 and the series coil33 of said relay is connected, in series with a suit able resistance 34and resonated by a condenser 35, between line 1. and neutral N thevoltage across which is in phase with V1: and as shown in the vectordiagram (Figure 8) is normally in quadrature with volta e V2 2 appliedacross the voltage coil 32. The coils 32 and 33 may be the voltage andcurrent cells respectively of a watt-hour meter provided with two pairsof contacts 65 and 66 closable by rotation of its disc 83 in either ofthe two directions. The contacts 65 and 63 can be arranged torespectively energize coils II and 12 from a battery 13 for controllingthe closing and opening of a switch ll. As shown, the switch 14 canbe'used for turning The current in the series coil 33 and thus theseries coil flux is in phase with the voltage V1: and by means of thepower factor adjustment on the meter the age V1: and thus the seriescoil flux remains undisturbed but as hereinbefore described a quadraturecomponent v is introduced into the voltage V2 3 which produces a torqueon the meter disc and closes one pair of the said contacts. When anauxiliary voltage of opppsite phase to the voltage 0 is introduced intohigh tension line 3 the meter disc turns in the opposite direction andcloses the other pair of contacts as will be understood.

According to the modification illustrated in Figure 9 the voltage coil32 of a relay or watt hour meter, 62 described hereinbefore, is includedin a balanced circuit associated with the affected lines 2 and 3 in suchmanner that no current flows in the coil 32 except under the disturbedphase conditions resulting from the transmission of a signal. The saidcircuit comprises two oondensers 36 and 31 connected in series acrossthe lines 2 and 3 the voltage coil 32 being connected at one end to thejunction between said condensers 36 and 31 and at its other end to apoint between a condenser 38 and resistance 39 connected in seriesbetween line 2 and neutral N. By suitably choosing the values of thecondensers 36, 31 and 38 and the resistance 33, the voltage at each endof the voltage coil 32 can be equalised under normal conditions so thatno current flows through the coil 32. A phase disturbance, will,however, upset the balance of the circuit so that a current will flowthrough the coil 32. The coil 32 cooperating with a coil 61 of the relay62 will then move the disc 63 in adlrection according to the characterof the phase disturbance.

In another form of circuit shown in'Figure 10 for achieving the sameresult an inductive resistance l0 and a condenser 4| are connected inseries between one of the affected lines say line 2 and neutral, thecondenser ll being connected to neutral. The voltage coil 32 of therelay 32 is then connected from the juncti'on'between the inductiveresistance 40 and the condenser H to the other one (3 'of the afiectedlines. The values of the inductive resistanc 40 and the condenser M arechosen such that the voltage at their junction is under normalconditions equal to that of the line 3 to which the voltage coil 32 isconnected. The coil 51 of the relay 32 is connected as shown andcooperates with the coil 32 to rotate the disc 63 as previouslydescribed.

A slightly different arrangement shown in Figure 11 comprises aninductive resistance 42 and a resistance 43 in series across theaffected lines 2 3 the voltage coil 32 of the relay 62, resonated'by acondenser 44 being connected from the junction between said inductiveresistance l2 and resistance 43 to neutral N.

a bridge connection from the junction between Q I the resistance 41 andthe condenser 48 to the loop connecting the other terminals of the backto back transformers l5 and 46. The primary of the transformer 56 isconnected across the affected lines 2 3 and the primary of transformer45 across the line I and neutral N. Under normal conditions, by asuitable choice of the circuit constants the voltages impressed on thevoltage coil 32 by each transformer can be made to balance, whichbalanceis upset by a phase disturbance acting upon the transformer 36.

We claim:

1. In a system for controlling from a control station operations at aremote station, in combination, a polyphase alternating current circuitinterconnecting said stations, means at said control station forcombining at the will of an operator an auxiliary voltage with aplurality of phase voltages of said circuit to produce resultantvoltages out of phase with said phase voltages, and

'the phase of a plurality of the phase voltages of said circuit,transformer means at said remote station having a plurality of primarywinding means at said remote station energized from said circuit andresponsive to said resultant voltages. I

2. In a system for controlling from a control station operations at aremote station, in combination, a polyphase alternating current circuitinterconnecting said stations, means at said control station for addingor subtracting at the will of an operator an auxiliary voltage to orfrom a plurality of phase voltages of said circuit to produce resultantvoltages out of phase with said phase voltages, and means at said remotestation energized from said circuit and responsive to said resultantvoltages.

3. In a system for controlling from a control station operations at aremote station, in combination, a three phase alternating currentcircuit interconnecting said stations, means at said control station forderiving a voltage from one phase of said circuit and applying the sameto the other two phases so as to vary at the will of an operator thephase relation of the voltages of said two phases with respect to thevoltage of said one phase, and means at said remote station energizedfrom said circuit and responsive to the variation of said phase relationof the voltages of said two phases.

4, In a system for controlling from a control station operations at aremote station, in combination, athree phase alternating curre'ntcircuitinterconnecting said stations, means at said control station forderiving a voltage from one phase of said circuit and applying thesameto the other two phases so as to advance or retard at the will meansconnected to be energized from different phases of said, circuit andsecondary winding means into which no voltage is induced as long as thephase of said plurality of phase voltages remains unchanged, a movablemember, and a pair of windings operatively related to said movablemember, one of said pair of windings being connected for energization tosaid secondary winding means and the other being connected forenergization to said circuit.

6. In a system for controlling from a control station operations at aremote station, in combination, a polyphase alternating current circuitinterconnecting said stations, means at said control station for varyingat the will of an operator the phase of a plurality of the phasevoltages of said circuit, a movable member at said remote station, and apair of winding means operatively related to said movable member, one ofsaid winding means being connected for energization to said circuit andthe other being connected for energization between one phase of saidcircuit and a neutral point thereof to effect movement of said'movablemember only when the phase of said plurality of phase voltages ischanged by the 0per'ator.

7. In a system for controlling from a control station operations at aremote station, in combination, a polyphase alternating current circuitinterconnecting said stations, means at said con trol station forvarying at the will of an operator the phase of a plurality of the phasevoltages of said circuit, a movable member at said remote station, apair of winding means operatively related to said movable member, one ofsaid winding means being connected for energization to v said circuit,and a balanced circuit including the tion energized from said circuitand responsive to the advance or retardation'of said phase relation ofthe voltages of said two phases.

other of said winding means connected for energization between saidpolyphase circuit and a neutral point thereof sothat no current flows insaid'other winding means as long as the phase of said plurality of phasevoltages remains unchanged. 7

' GILBERT .GILLIVER.

GEORGE FRANK TAGG. GEORGEFREDERICK SHOT'I'ER.

